Re: How do you keep dry flies, well, dry?
For most situations, there are patterns that will do the job and also float well.
Before my dry fly ever touches the water, I always put some floatant on finger and work it into the fly really well. Not too much floatant though or it can actually cause the fly to sink. Right now I'm partial to Fly Sauce, though I have used Loon Aquel and Gink. I do a couple false casts before I set the fly down on the water for the first time.
I'm cheap (read penniless) so I haven't bought a shake and float type powder or desiccant to use when the flies get water logged. You can make something similar by using the little silica gel packets that come with some products and a film canister. This works especially well with foam flies and also works with all but the smaller standard style dry flies. I reapply floatant after drying the fly out with this.
You can take your dry shirt and squeeze foam flies between it to get the water out before reapplying floatant as well. This works better with slightly larger foam flies though.